Figure 3.1 Meteor showers are rare, but the probability of them occurring can be calculated. (credit: modification of work “A meteor during the peak of the 2009 Leonid Meteor Shower” by Navicore/ Wikimedia Commons, CC BY 3.0) It is often necessary to…
Display Data A stem-and-leaf plot is a way to plot data and look at the distribution. In a stem-and-leaf plot, all data values within a class are visible. The advantage in a stem-and-leaf plot is that all values are listed, unlike a…
An important characteristic of any set of data is the variation in the data. In some data sets, the data values are concentrated closely near the mean; in other data sets, the data values are more widely spread out from…
Consider the following data set.4; 5; 6; 6; 6; 7; 7; 7; 7; 7; 7; 8; 8; 8; 9; 10 This data set can be represented by following histogram. Each interval has width one, and each value is located in…
The mean (Arithmetic), median and mode are all measures of the “center” of the data, the “average”. They are all in their own way trying to measure the “common” point within the data, that which is “normal”. In the case…
Formula for Population Mean μ=1N∑i=1Nxiμ=1N∑i=1Nxi Formula for Sample Mean x–=1n∑i=1nxix–=1n∑i=1nxi This unit is here to remind you of material that you once studied and said at the time “I am sure that I will never need this!” Here are the…
The “center” of a data set is also a way of describing location. The two most widely used measures of the “center” of the data are the mean (average) and the median. To calculate the mean weight of 50 people, add the 50 weights together…
The common measures of location are quartiles and percentiles. Quartiles divide an ordered data set into four equal parts. The three quartiles of a data set are labeled as Q1, Q2, and Q3. In the same way, percentiles divide a data set into…
Stem-and-Leaf Graphs (Stemplots), Line Graphs, and Bar Graphs One simple graph, the stem-and-leaf graph or stemplot, comes from the field of exploratory data analysis. It is a good choice when the data sets are small. To create the plot, divide each observation of…
Figure 2.1 When you have large amounts of data, you will need to organize it in a way that makes sense. These ballots from an election are rolled together with similar ballots to keep them organized. (credit: modification of work “HELMAND PROVINCE,…